Document feeding apparatus



Sept. 8, 1970 w. P. BOND 3,527,453

DOCUMENT FEEDING APPARATUS Filed May 9, 1968 BRAKE EN ERG\Z\NG mn- Z5 52I \Mui s1 MLF 24 22 F162. FIGS.

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ATTORNEYS United States Patent 3,527,458 DOCUMENT FEEDING APPARATUSWilliam Percy Bond, Langford, England, assignor to InternationalComputers and Tabulators Limited, London, England, a British companyFiled May 9, 1968, Ser. No. 727,886 Claims priority, application GreatBritain, May 16, 1967, 22,614/67 Int. Cl. B6511 3/08 U.S. Cl. 271-30 7Claims ABSTRACT OF THE DISCLOSURE A stack of documents is supported,with the documents on edge, on a sloping support member having aslightly upturned lower end. A weighted carriage, moveable down theslope under gravity, supports the upper end of the stack and the weightof the carriage is such that it cooperates with the upturned end of thesupport member to maintain the lower end of the document stack in asubstantially constant position relative to the lower end as documentsare fed in succession off the lower face of the stack. An air-jetfeeding arrangement is used to select and feed these documents. Wherethe documents have more resistance to movement down the slope, the slopeand/or the carriage Weight may be increased, and in this case aspring-biassed electromagnetically-released brake may be controlled by aswitch at the upturned end to alternately operate and release thecarriage in dependence upon the presence or absence of documents at theup turned end.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to document feeding apparatus, and in particular to apparatusfor feeding documents from one face of a stack.

Description of the prior art A number of examples of apparatus formaintaining a stack of documents with the feeding face of the stack at apredetermined pick-off point are known. Usually, however, particularlyin the case of so-called constant height pile-tables, where the documentat the feeding face of the stack is required to be completely free to befed away from the stack, it has previously been proposed to support thestack more or less vertically, with the individual documentshorizontally in the stack, and to employ a positive mechanical drive tobodily raise the stack as documents are removed from its top face. Thus,this kind of stack supporting arrangement is relatively complex andcostly.

Where apparatus has required documents to be stacked vertically, ornearly so, so that the document stack approaches the horizontal, orwhere the stack is inverted so that documents are fed from the lower endof the stack, it has previously been proposed to provide means forpositively retaining the documents in the stack. In these cases thedocument feeding means has used devices, such as picker knives orsuction caps which are required to be mechanically controlled to engagea document to be fed in order to withdraw the document from theretaining means. Thus, this kind of document feeder also requires afairly complex feeding mechanism.

SUMMARY OF THE INVENTION According to the present invention, documentfeeding apparatus includes means for supporting a stack of documentseach on one edge, the document support means being inclined generally atan angle from horizontal,

the lower end of said document support means being formed into a shallowupward bend; a weighted carriage supported on said document supportmeans for movement down the incline under the influence of gravity tourge the stack of documents towards the lower end, the weight of thecarriage being so adjusted that the carriage coacts with said upwardbend to maintain the document stack with one face at a substantiallyconstant position relative to the lower end of the support means; andmeans for selecting and feeding documents in succession from said oneface of the stack.

Thus, in this apparatus, the documents at that face of the stack fromwhich documents are fed are not positively retained but are completelyfreely supported. This allows the use of a very simple air jet for thepurposes of separation and feeding of each document in turn.

Where the documents are large or thick, for example, it may be desirablethat the force exerted on the stack to move it towards the feeding endof the support means be increased, as by increasing the weight of thecarriage or by increasing the slope of the incline, and in this case itmay be desirable to reduce the application of this force while the stackis correctly positioned on the support means. For this purpose thecarriage may be fitted with a brake normally biassed to arrest movementof the carriage and means is then provided for releasing the brake whendocuments are absent from the upward bend of the support means. Suchbrake releasing means may include means (such as mechanically-operatedswitch) for detecting the presence or absence of documents at the upwardbend, the detecting means being inserted in the energizing circuit foran electromagnetically-operated brake release arrangement. It has alsobeen found advantageous under some conditions to energize such anelectromagnet by a succession of electrical impulses.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 shows, diagrammatically, a document feeding arrangement,

FIG. 2 shows a modification of part of the arrangement of FIG. 1, and

FIG. 3 is a schematic circuit diagram.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the FIG. 1 ofthe drawing, a support member 1 is arranged at a small angle fromhorizontal, and the lower end of the member 1 is smoothly curved into ashallow upward bend. In use documents 9 are stacked on edge along thesupport member 1. A carriage 2, consisting of a base block 3 and a stacksupport plate 4 is mounted on rollers 5 so that it is free to move alongthe support member 1. The rollers 5 run in guide grooves 6 in the member1.

A feed bed 7 is provided having one end adjacent the curved end of thesupport member 1 extending above the member 1 and lying substantiallyparallel to the stack support plate 4. The bed 7 carries an aligningstop 8 positioned above the maximum height of the documents 9 of thestack on the support member 1.

The feed bed 7 also carries a number of apertures 10 arranged along itslength. One side of the bed 7 forms a feeding face 11 and sheets are fedin succession along a feed path lying close to the face 11 of the bed 7.Only one aperture 10 is shown in the drawing. The apertures 10 areconnected on the side of the bed 7 remote from the face 11, by means ofbranch tubes 12 to a manifold 13, and the manifold 13 is coupled to aninlet pipe 14 from a source of air under pressure (not shown). All theapertures 10 are arranged at an angle with respect to the 3 feeding face11 of the feed bed 7, the angle being chosen so that'air issuing fromthe apertures emerges through the feeding face 11 as an air jet with acomponent of motion in the direction in which sheets are required tomove along the bed 7.

Two further apertures and 16 are provided in the feed bed 7 opposite theposition occupied by sheets 9. The aperture 15 is angled in the same wayas are the apertures 10 and is connected'through a valve 17 to the airinlet pipe 14. The aperture 16 is also arranged at an angle to the face11 of the feed bed, but in this case the angle is chosen so that an airjet issuing from the aperture 16 has a component of motion in theopposite direction from the normal sheet feeding direction. The aperture16 is connected to the air inlet pipe 14 through a second valve 18.

The valves 17 and 18 are interconnected by an operating linkage 19 soarranged that it has two effective positions. In one position valve 17is open and valve 18 is closed while in the second position, valve 17 isclosed and valve 18 is open.

A pipe is provided and is connected at one end to the manifold 13. Thefree end of the pipe 20 is curved to a position in which a stream of airissuing from it impinges on the edges of those documents 9 of the stackwhich are supported on the bend of the support member 1, nearest to thefeed bed 7.

The curvature of the bend of the support member 1 is so chosen inconjunction with the weight of the carriage 2 and the angle of thesupport member 1, that, with the stack of documents 9 upon the supportmember 1, the carriage 2 acts on the stack to maintain the free end ofthe stack in a substantially constant position relative to the end ofthe support member 1 and hence to the feed bed 7.

In operation, air is supplied under pressure to the inlet 14, the valveoperating linkage 19 is adjusted to an initial position in which thevalve 18 is open while the valve 17 is closed, and a stack of documents9 is placed in position on the support member 1, the stack beingarranged, as shown, so that all the documents 9 are supported on end.The carriage 2 is then allowed to move under the influence of gravity,along the member 1 to support one end of the stack. The carrier 2 thenmoves the stack along the member 1 so that the end of the stack nearestto the feed bed 7 occupies its correct position near the bed 7. At thispoint an air stream issuing from the pipe 20 acts on the documents 9 atthe feeding end of the stack, and assists in separating these documents9 from each other and from the stack.

An air jet issuing from the aperture 16 then, by providing a pressuredifferential across the gap between the bed 7 and the end of the stackof documents 9 causes the nearest document 9 to be attracted towards thebed 7. At the same time the component of motion of the air jet acting inthis opposite direction to the normal document feeding direction causesthe attracted document 9 to be moved to the position indicated at 9a bya broken line, with its upper edge abutting the alignment sto 8. Thus,the end document 9 of the stack is extracted from the stack and isaligned with the stop 8.

The operating linkage 19 is now moved to its second position, so thatvalve 17 is opened and valve 18 is closed. The extracted and aligneddocument 9 is now moved under the influence first of an air jet fromaperture 15 and subsequently of jets from the apertures 10 along thefeed bed 7 to follow the required feed path.

It will be realised that the feeding of an aligned document is initiatedby the actuation of the linkage 19, and that the normal practice will befor the linkage 19 to be actuated as required by the apparatus to whichthe sheets are to be fed. Thus, the linkage 19 is normally to becontrolled by whatever document utilization apparatus is to be suppliedby the present feeding device, such as a document reading or sortingapparatus, for example.

It will be appreciated that since the purpose of the linkage 19 is tocontrol the application and direction of air jets issuing from the bed7, this purpose may alternatively be achieved by varying the directionof a single applied air jet instead of by the switching of the airsupply.

Moreover one or more air jets may be controlled for this purpose byother means than a purely mechanical linkage. For example, valves may becontrolled electromagnetically. Alternatively, the application ordiversion of air jets or streams may he controlled by a fluid amplifieror by other fluid logic devices. I

It will be appreciated from the foregoing description that the combinedaction of the inclined stack support member 1 with its upward bend andthe carriage 2 is to support the stack so that the next document 9 to befed from the lower end is maintained in position to be selected and fedby an air jet, such as the jet from the aperture 16. The next document 9is free from any restraint in order to enable its selection without theneed for any mechanical operation to be performed. The aid stream fromthe pipe 20 assists in the separation of documents 9 at the upward bendof the support member 1, but it is to be understood that this auxiliaryseparation is not necessary in all cases.

The maintenance of the position of the document stack is dependent, asnoted above, upon the relationship of the weight of the carriage 2,which tends to move the stack down the incline of the member 1, to theresistance to the movement of the stack offered by the upward bend ofthe member 1. However, particularly where the documents in the stack arelarge or relatively individually heavy, it may happen that the forcerequired to be exerted upon the stack by the carriage 2 to initiatemovement of the stack is so great that, once moving, the end downwardsof the stack will tend to overspill off the end of the support member 1.Under these circumstances the apparatus may be modified as indicated inFIGS. 2 and 3 to relieve the down ward pressure on the stack exerted bythe carriage 2 while the stack of documents 9 is correctly positioned onthe support member 1.

In this case, as indicated in FIG 2, the support member 1 is mounted ona pivoted block 21, and is adjustable by a worm gear 22 meshing withteeth 23 formed on the block 21 to vary its angle of inclination. Theworm gear 22 is mounted on a shaft 24 supported in bearings 25, theshaft 24 being rotatable under control of a hand wheel 26.

The carriage 2 includes a brake shoe 27 biassed by a spring 28 to act onone of the carriage rollers 5. An electromagnet 29 has an armature 30connected to the brake shoe 27, the arrangement being such thatenergization of the electromagnet 29 causes the brake shoe 27 to bereleased from the roller 5.

A normally-closed microswitch 31 is supported on a bracket 32 beneaththe support member 1 and has an operating lever 33 projecting throughthe support member 1 into the path of documents 9 in the stack at theupward bend.

In operation, the angle of inclination of the support member isincreased, when dealing with a stack of large documents 9, and/or theweight of the carriage 2 is increased so that with the brake shoe 27released from the roller 5, a stack of documents supported on the member1 above the upward bend is moved from rest under the influence of thecarriage 2. If the brake shoe 27 were maintained released, there wouldbe a tendency, as the number of documents in the stack is diminished,for upward bend to fail to hold back the stack against the carriage 2.For this reason the brake shoe electromagnet 29 is connected to anenergizing source 34 in series with the microswitch 31, as shown in FIG.3. Thus, as the leading documents 9 of the stack are advanced to theupward bend in the support member 1 they actuate the switch 31 to openthe energizing circuit for the electromagnet 29, allowing the brake shoe27 to engage the carriage roller 5. The carriage is then held by thebrake until the leading documents at the feeding face of the stack havebeen removed from the stack, when the switch 31 re-closes and the brakeis again released.

It is preferred that the energizing source 34 is a pulse generator,providing electrical impulses to actuate the electromagnet 27. Thefrequency of generation of these impulses is far from critical, since aswill be realised, a constant energizing current may alternatively beused but a frequency of a few impulses, say, four or five per second hasbeen found to yield good results.

It will also be appreciated that the provision of means for varying theangle of inclination is not essential to the present invention. Forexample, if the feeding apparatus is to be used exclusively fordocuments of a particular kind, then the angle of the support member,and the weight applied to the carriage may be predetermined and notthenceforward varied. Similarly, it will also be appreciatetl that wherethe size of stack to be handled is fairly small, so that there is nogreat difference in force required to move the maximum or minimumlengths of stack down the incline then the balance between appliedweight of the carriage 2 and resistance to stack movement offered by theupward of the support member may well be sufficient to ensure correctstack positioning without the need for the brake shoe 27 or the brakecontrol described.

I claim:

1. Document feeding apparatus including means for supporting a stack ofdocuments each on one edge, the document support means being inclinedgenerally at an angle from horizontal, the lower end of said documentsupport means being formed into a shallow upward bend; a weightedcarriage supported on said document support means for movement down theincline under the influence of gravity to urge the stack of documentstowards the lower end, the weight of the carriage being so adjusted thatthe carriage co-acts with said upward bend to maintain the documentstack with one face at a substantially constant position relative to thelower end of the support means; means for feeding documents insuccession from said one face of the stack; a brake on said carriage;means for normally biasing the brake to arrest movement of the carriage;and means for detecting the presence of documents at the upward bend,the detecting means being operative to release the brake in response tothe absence of documents at said upward bend.

2. Apparatus as claimed in claim 1 in which said brake is spring biasedto brake the carriage, includnig an electromagnet energizable to releasethe brake, means for energizing the electromagnet and a switch connectedbetween the brake and the energizing means, the switch being operable bythe presence of documents at said upward bend to interrupt theconnection from the energizing means to the electromagnet.

3. Apparatus as claimed in claim 2, in which said energizing meansincludes means for generating a succession of electrical impulses at apredetermined frequency to energize said electromagnet.

4. Apparatus as claimed in claim 1 further including means for varyingthe inclination of said document support means.

5. Document feeding apparatus including a document support member forsupporting one edge of each document of a stack of documents; a firstportion of the support member inclined to the horizontal in a firstsense and having a lower edge; a second portion of the support memberinclined to the horizontal in a second sense opposite to said firstsense and having a lower edge joined to the lower edge of the firstportion; a weighted carriage supported on said first portion; means onsaid carriage operative to engage a rear end of the stack of documentsand support the documents in planes inclined to the vertical in thesecond sense; the weighted carriage being effective to urge thedocuments to move down the inclined first portion and thence up theinclined second portion to maintain a front end of the stack at asubstantially constant position on the second portion; and feed meansoperable to feed documents in succession from the front end of thestack.

6. Document feeding apparatus as claimed in claim 5 including a documentfeed bed having a feeding face substantially parallel to said planes andspaced from said substantially constant position; and first air meansoperable to produce a first air jet issuing from the feeding face of thefeed bed having a component of motion along the feeding face andeffective to feed the documents from the front of the stack insuccession in a direction aligned with said component of motion.

7. Document feeding apparatus as claimed in claim 6 including second airmeans operable to produce a second air means operable to produce asecond air jet issuing from the feeding face of the feed bed having acomponent of motion along the feeding face in opposition to thecomponent of motion of the first air jet; a document stop on the feedbed; and control means selec-- tively operable to render said first airmeans operative to feed a document from the front of the stack intoabutment with the stop and subsequently to render the second air meansoperative to feed the document away from the stop along the feed bed.

RICHARD E. AEGERTER, Primary Examiner

